Fuel cell power plant for mobile unit

• US 20030180583A1
• Filed: 01/07/2003
• Published: 09/25/2003
• Est. Priority Date: 08/30/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Ichikawa, Hiroyuki, Iwasaki, Yasukazu
• Granted Patent: US 6,994,931 B2
• Time in Patent Office: Days
• US Class Current: 429/9
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 58/31 for starting of fuel cells
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: B60L 58/34 by heating
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/04225 during start-up
• CPC Class Codes: H01M 8/04302 applied during start-up
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A fuel cell power plant is provided for a mobile unit. The mobile unit is provided with a drive device (29) driving the mobile unit when supplied with electrical power. The power plant comprises a fuel cell (21) generating power when supplied with fuel, a battery (27) charged with power generated by the fuel cell, a power regulation device (31) selectively distributing power from the fuel cell (21) and the battery (27) to the drive device (29), and a controller (33) for controlling running operations. The controller (33) estimates the energy required to activate the fuel cell (21), and controls the power regulation device (31) when the energy required to activate the fuel cell is greater than or equal to a determination value so that the fuel cell is not activated and power from the battery (27) is supplied to the drive device (29). In this manner, it is possible to prevent unnecessary power consumption during startup operations.

Claims

1. A fuel cell power plant for a mobile unit, the mobile unit provided with a drive device(29) driving the mobile unit when supplied with electrical power, the power plant comprising:

a fuel cell(21) generating power when supplied with fuel;

a battery (27)charged with power generated by the fuel cell;

a power regulation device(31) selectively distributing power from the fuel cell and the battery to the drive device;

a controller(33) functioning to

estimate the energy required to activate the fuel cell;

set a determination value corresponding to a relatively small amount of energy in comparison to the energy required to drive the fuel cell; and

control the fuel cell and the power regulation device so that the fuel cell is not activated and power from the battery is supplied to the drive device when the estimated energy required to activate the fuel cell is greater than or equal to the determination value.

2. The power plant as defined in claim 1, wherein the controller(33) activates the fuel cell(21) when the estimated energy required to activate the fuel cell is less than the determination value.

3. The power plant as defined in claim 1 or claim 2, wherein the determination value is set to a value corresponding to approximately 10% of the maximum value of the energy required to complete activation of the fuel cell(21) under cold conditions.

4. The power plant as defined in claim 1, further comprising a sensor (40) for detecting the temperature of the fuel cell (21);

and wherein the controller(33) estimates the energy required to activate the fuel cell based on the temperature of the fuel cell.

5. The power plant as defined in claim 1, further comprising a timer for measuring time;

and wherein the controller(33) estimates the energy required for activation of the fuel cell(21) based on the time from stopping the fuel cell on an immediately previous occasion to activating the fuel cell on the present occasion.

6. The power plant as defined in claim 1, further comprising a sensor(41) for detecting an external temperature;

and wherein the controller (33)estimates the energy required for activating the fuel cell(21) based on the external temperature.

7. The power plant as defined in claim 1, further comprising a SOC sensor (39)for detecting the SOC of the battery(27);

and wherein the controller(33)

sets a lower limiting value permitted for the SOC of the battery; and

activates the fuel cell without reference to the energy required for the activation of the fuel cell(21) when the detected SOC is less than or equal to the lower limiting value.

8. A fuel cell power plant for a mobile unit, the mobile unit provided with a drive device(29) driving the mobile unit when supplied with electrical power, the power plant comprising:

a fuel cell(21) generating power when supplied with fuel;

a battery(27) charged with power generated by the fuel cell;

a power regulation device(31) selectively distributing power from the fuel cell and the battery to the drive device;

a controller(33) functioning to

determine a short-term operation running mode or a normal running mode;

activate the fuel cell when a normal running mode is determined from the determination result; and

control the fuel cell and the power regulation device so that the fuel cell is not activated and power from the battery is supplied to the drive device when the short-term operation running mode is determined.

9. The power plant as defined in claim 8, further comprising at least one of

a timer(33) for measuring the time after starting the power plant;

a sensor(38) for detecting the vehicle running speed;

a sensor(37) for detecting the depression amount of the accelerator pedal;

a sensor(37) for detecting the depression speed of the accelerator pedal;

a sensor(39) for detecting the SOC of the battery; and

wherein

the controller(33) determines the short-term operation running mode or the normal running mode based on at least one of the detection values.

10. The power plant as defined in claim 9, wherein the controller(33) determines the normal running mode when any one of the following conditions are satisfied:

when the measured time is long, when the vehicle speed is high, when the accelerator pedal depression amount is large, when the speed of depressing the accelerator pedal is high or when the power consumption by the battery is large.

11. The power plant as defined in claim 8, further comprising

a calendar(57A) measuring the date;

a clock(57B) measuring the time;

a GPS(57C) measuring position; and

wherein

the controller(33) uses a learning control routine to store a date/time pattern of the vehicle by combining the output values from one or more of the above components; and

determines the normal running mode or the short-term operation running mode based on any one current output value in the stored date/time running pattern.

12. A fuel cell power plant for a mobile unit, the mobile unit provided with a drive device(29) driving the mobile unit when supplied with electrical power, the power plant comprising:

a fuel cell(21) generating power when supplied with fuel;

a battery(27) charged with power generated by the fuel cell;

a power regulation device(31) selectively distributing power from the fuel cell and the battery to the drive device;

a switch(51) allowing selection of a normal running mode or a short-term operation running mode; and

a controller(33) functioning to

control the fuel cell and the power regulation device so that the fuel cell is not activated and power from the battery is supplied to the drive device when the short-term operation running mode is selected.

13. The power plant as defined in claim 12, wherein the controller(33) both activates the fuel cell(21) and controls the power regulation device(31) so that power from the battery(27) is supplied to the drive device(29) when the normal running mode is selected.

14. The power plant as defined in claim 12, further comprising a sensor for detecting the SOC of the battery(39);

and wherein the controller(33) determines whether or not to activate the fuel cell(21) based on the detected residual charge in the battery when the short-term operation running mode is selected.

15. The power plant as defined in claim 14, wherein the controller(33) activates the fuel cell(21) even when the short-term operation running mode is selected if the detected residual battery charge is low.

16. A fuel cell power plant for a mobile unit, the mobile unit provided with a drive device(29) driving the mobile unit when supplied with electrical power, the power plant comprising:

a fuel cell(21) generating power when supplied with fuel;

a battery(27) charged with power generated by the fuel cell;

a sensor(39) for detecting the SOC of the battery;

a power regulation device(31) selectively distributing power from the fuel cell and the battery to the drive device;

a switch(51) allowing selection of a normal running mode or a short-term operation running mode; and

a controller(33) functioning to

estimate the energy required to activate the fuel cell;

estimate the time until completion of activation based on the energy required to activate the fuel cell;

estimate the power consumption during vehicle operation until the estimated time for fuel cell activation elapses;

control the fuel cell and the power regulation device so that the fuel cell is not activated and power from the battery is supplied to the drive device when the short-term operation running mode is selected if the residual battery charge is greater than the estimated power consumption; and

activate the fuel cell even when the short-term operation running mode is selected if the residual battery charge is less than the estimated power consumption.

17. The power plant as defined in claim 16, further comprising a device performing voice display or visual display(55);

and

wherein the controller(33) at least notifies the driver by a voice display or visual display that the fuel cell(21) is being activated or that activation has been completed, when the short-term operation running mode is selected